Interleukin-25 (IL-25), also known as IL-17E, is a cytokine that belongs to the IL-17 cytokine family and is secreted by type 2 helper T cells (Th2) and mast cells. IL-25 induces the production of other cytokines, including IL-4, IL-5 and IL-13, in multiple tissues and stimulates the expansion of eosinophils.
IL-25 has been implicated in chronic inflammation associated with the gastrointestinal tract and the IL-25 gene has been identified in a chromosomal region associated with autoimmune diseases of the gut, such as inflammatory bowel disease (IBD). Conventional therapies for treatment of IBD involve either antibiotics or steroid-derived drugs; however these are not currently successful in inducing or maintaining clinical remission in patients.
IL-25 has also been shown to be upregulated in samples from patients with asthma, a condition estimated to affect more than 300 million people worldwide, suggesting that overexpression of this cytokine contributes to the pathology of asthma and related conditions.
Thus, there is a need for effective antagonists of IL-25 that are useful in the treatment of diseases and conditions characterized by IL-25 overexpression, including asthma and inflammatory bowel disease.